Belgian police officers stand guard in a cordoned off area outside the Brussels Central Station after a small explosion in Brussels, Belgium, on June 20, 2017. The Brussels Central Station was evacuated Tuesday evening after a small explosion occurred within the station, local authorities confirmed. (Xinhua/Ye Pingfan)

A small explosion that occurred Tuesday evening within the Central Station of Brussels, the capital of Belgium, was considered a terrorist attack, a spokesperson of the Belgian federal prosecutor's office told reporters.

Eric Van Der Sypt, the spokesperson, confirmed at a press briefing on late Tuesday that the man who caused the explosion was "neutralized" by soldiers, but did not reveal whether the man is dead or alive.

The identity of the man remains unknown.

The explosion did not cause any injuries, as the explosives used were of "relatively low intensity," said the spokesman.

The explosives disposal unit of the Belgian security service is carrying out a checkout at the station, the Belgian crisis center announced on its Twitter account around 23:20 local time (2120 GMT), but stressed that the situation is under control.

The explosion occurred shortly before 21:00 local time (1900 GMT).

Local media quoted some witnesses as saying that the explosion was caused by a man with an explosive belt.

Unconfirmed sources say that the man was shot.

A witness told local media that the man was seen lying on the floor inside the station, with wires coming out of his clothes.

Soon after the explosion, the Central Station, the busiest railway station in Brussels, was evacuated Tuesday evening. And the nearby Grand Place, a popular tourist destination, was also evacuated, local authorities confirmed.

The metro lines 1 and 5, which pass through the station, were closed following police orders.

A large number of police and soldiers are deployed around these two sites in the heart of Brussels.

The security threat alert level in Belgium currently stands at 3, the second highest.

As the capital of the European Union (EU), Brussels hosts the major political institutions of the EU. It has been on high alert after suicide attacks hit the city's airport and metro systems on March 22, 2016, which left 32 people dead and many more injured.